Calculating the phase angle?

Question

if the current waveform is i=10cos(314t-60degrees)
and the voltage waveform v=50sin(314t-45degrees)
then the phase difference is said to be 75 degrees but how do u get this?
the answer says 30degrees - (-45degrees)

Answer 1

First I would change i=10cos(314t-60degrees) to i=10sin(314t+30degrees). Then comparing the "+30" to "-45" the difference is 75 degrees.

Answer 2

take the phasor,and plot it.

convert first cosine to sine wave. that will yield an angle of +30 degrees for the current. the voltage would be -45 degrees.If you align that to get the phase dif, in phasor form that would be 30- (-45) =75